https://gcc.gnu.org/g:37980a5a781bf7a8831b6f106ef61f11a52579d0

commit r16-7888-g37980a5a781bf7a8831b6f106ef61f11a52579d0
Author: Philipp Tomsich <[email protected]>
Date:   Wed Mar 4 09:49:09 2026 +0100

    avoid-store-forwarding: Clear sbitmap before use [PR124351]
    
    The forwarded_bytes sbitmap needs to be zeroed after allocation,
    as sbitmaps are not implicitly initialized.  This caused valgrind
    warnings about conditional jumps depending on uninitialised values.
    
    gcc/ChangeLog:
    
            PR rtl-optimization/124351
            * avoid-store-forwarding.cc (process_store_forwarding): Add
            bitmap_clear after allocating forwarded_bytes.

Diff:
---
 gcc/avoid-store-forwarding.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/avoid-store-forwarding.cc b/gcc/avoid-store-forwarding.cc
index f9c43a2ec460..75ba30a62eb5 100644
--- a/gcc/avoid-store-forwarding.cc
+++ b/gcc/avoid-store-forwarding.cc
@@ -177,6 +177,8 @@ process_store_forwarding (vec<store_fwd_info> &stores, 
rtx_insn *load_insn,
      by later stores.  */
 
   auto_sbitmap forwarded_bytes (load_size);
+  bitmap_clear (forwarded_bytes);
+
   unsigned int i;
   store_fwd_info* it;
   auto_vec<store_fwd_info> redundant_stores;

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